/// <summary>BER encode class value.</summary>
/// <param name="buffer">Target buffer. Value is appended to the end of it.</param>
public override void Encode(MutableByte buffer)
{
MutableByte tmp = new MutableByte();
byte[] b = BitConverter.GetBytes(value);
for (int i = 3; i >= 0; i--)
{
if (b[i] != 0 || tmp.Length > 0)
{
tmp.Append(b[i]);
}
}
if (tmp.Length > 0 && (tmp[0] & 0x80) != 0)
{
tmp.Prepend(0);
}
else if (tmp.Length == 0)
{
tmp.Append(0);
}
BuildHeader(buffer, Type, tmp.Length);
buffer.Append(tmp);
}
/// <summary>
/// Wrap BER encoded SNMP information contained in the parameter <see cref="MutableByte"/> class.
///
/// Information in the parameter is prepended by the SNMP version field and wrapped in a sequence header.
///
/// Derived classes call this method to finalize SNMP packet encoding.
/// </summary>
/// <param name="buffer">Buffer containing BER encoded SNMP information</param>
public virtual void encode(MutableByte buffer)
{
// Encode SNMP protocol version
MutableByte temp = new MutableByte();
_protocolVersion.encode(temp);
buffer.Prepend(temp);
temp.Reset();
AsnType.BuildHeader(temp, SnmpConstants.SMI_SEQUENCE, buffer.Length);
buffer.Prepend(temp);
}
/// <summary>ASN.1 encode SNMP version 1 trap</summary>
/// <param name="buffer"><see cref="MutableByte"/> buffer to the end of which encoded values are appended.</param>
public override void encode(MutableByte buffer)
{
MutableByte trapBuffer = new MutableByte();
// encode the enterprise id & address
_enterprise.encode(trapBuffer);
_agentAddr.encode(trapBuffer);
_generic.encode(trapBuffer);
_specific.encode(trapBuffer);
_timeStamp.encode(trapBuffer);
_variables.encode(trapBuffer);
MutableByte tmpBuffer = new MutableByte();
BuildHeader(tmpBuffer, (byte)PduType.Trap, trapBuffer.Length);
trapBuffer.Prepend(tmpBuffer);
buffer.Append(trapBuffer);
}
/// <summary>
/// Used to encode the integer value into an ASN.1 buffer.
/// The passed encoder defines the method for encoding the
/// data.
/// </summary>
/// <param name="buffer">Buffer target to write the encoded data</param>
public override void Encode(MutableByte buffer)
{
int val = value;
byte[] b = BitConverter.GetBytes(value);
MutableByte tmp = new MutableByte();
// if value is negative
if (val < 0)
{
for (int i = 3; i >= 0; i--)
{
if (tmp.Length > 0 || b[i] != 0xff)
{
tmp.Append(b[i]);
}
}
if (tmp.Length == 0)
{
// if the value is -1 then all bytes in an integer are 0xff and will be skipped above
tmp.Append(0xff);
}
// make sure value is negative
if ((tmp[0] & 0x80) == 0)
{
tmp.Prepend(0xff);
}
}
else if (val == 0)
{
// this is just a shortcut to save processing time
tmp.Append(0);
}
else
{
// byte[] b = BitConverter.GetBytes(val);
for (int i = 3; i >= 0; i--)
{
if (b[i] != 0 || tmp.Length > 0)
{
tmp.Append(b[i]);
}
}
// if buffer length is 0 then value is 0 and we have to add it to the buffer
if (tmp.Length == 0)
{
tmp.Append(0);
}
else
{
if ((tmp[0] & 0x80) != 0)
{
// first bit of the first byte has to be 0 otherwise value is negative.
tmp.Prepend(0);
}
}
}
// check for 9 1s at the beginning of the encoded value
if (tmp.Length > 1 && tmp[0] == 0xff && (tmp[1] & 0x80) != 0)
{
tmp.Prepend(0);
}
BuildHeader(buffer, Type, tmp.Length);
buffer.Append(tmp);
}
/// <summary>
/// Encode SNMP packet for sending.
/// </summary>
/// <returns>BER encoded SNMP packet.</returns>
public override byte[] encode()
{
MutableByte buf = new MutableByte();
if (this.Pdu.Type != PduType.Get && this.Pdu.Type != PduType.GetNext &&
this.Pdu.Type != PduType.Set && this.Pdu.Type != PduType.V2Trap &&
this.Pdu.Type != PduType.Response && this.Pdu.Type != PduType.GetBulk &&
this.Pdu.Type != PduType.Inform)
throw new SnmpInvalidPduTypeException("Invalid SNMP PDU type while attempting to encode PDU: " + string.Format("0x{0:x2}", this.Pdu.Type));
// snmp version
_protocolVersion.encode(buf);
// community string
_snmpCommunity.encode(buf);
// pdu
_pdu.encode(buf);
// wrap the packet into a sequence
MutableByte tmpBuf = new MutableByte();
AsnType.BuildHeader(tmpBuf, SnmpConstants.SMI_SEQUENCE, buf.Length);
buf.Prepend(tmpBuf);
return buf;
}
